control of powers

It just sounds to me like the battle trance topic we have going on the forum. You should check it out Ares. If I'm not mistaken, Norse berserking is very much like you described. I assure you, it's very natural, as Awake said, it is adrenaline and in this case, fueled by anger.

Learning to control it is all about learning to control your own thoughts and emotions. Meditation and trance can help with that, as well as being observant and consciously aware of your action, thoughts and emotions. Most people don't realize how much they ignore the details of their mind, emotions and behavior. They just "do" with no awareness. Increase your awareness and you'll get the control you desire. Once we are aware of something, it is easy to change it or work toward it, depending on whether it is undesired or desired.